This invention relates to the field of rotary hoe tools, a plurality of which are mounted on a frame assembly for use as a field type agricultural implement.
Prior art tools of this general type include those disclosed in the following U.S. patents.
U.S. Pat. No. 4,114,697 discloses an agricultural implement having a plurality of finger elements of wire material mounted on a rotating hub, and a plurality of such hubs with finger elements mounted for rotational working contact with the ground on a frame assembly.
U.S. Pat. No. 3,139,049 discloses a power driven rotary plow comprising a plurality of plow shares affixed to respective spokes or arm members which are mounted for limited pivotal movement on a fully rotational hub.
U.S. Pat. No. 2,888,993 discloses a lawn edger having a plurality of nails extending from an annular rubber ring mounted on a rotatable hub.
U.S. Pat. No. 2,816,499 discloses a rotary tilling implement having a plurality of tines mounted for limited rotational movement on the rim of a wheel which rotates on the axle of a tilling implement. A plurality of such wheels are mounted on the axle of the tilling implement.
U.S. Pat. No. 2,603,139 discloses a rotary tilling apparatus having a plurality of hook-shaped tines mounted for limited pivotal movement on radial arm members extending from a rotatable hub mounted on an axle of the tilling apparatus.
U.S. Pat. No. 2,438,707 discloses a rotary tiller tooth and mounting which has a plurality of curved cutting blades of spring material mounted on a rotatable hub, each such cutting blade having a coil or torsion spring formed adjacent its connection to the hub to provide a spring back action when the cutting blades enter into and exit from the ground as the hub rotates.
U.S. Pat. No. 2,366,624 discloses a tine assembly in which a plurality of curved torsion spring tines are mounted on a rotatable hub in which the tines are resilient enough to spring back when contacting a stone or other immovable object embedded in the ground.
U.S. Pat. No. 2,199,954 discloses an agricultural implement for rotary tilling of the soil in which the tines or cutting tool members are mounted to a resilient rubber ring around a rotatable hub, wherein the rubber ring mounting provides resilience and flexibility to enable the cutting members to move both laterally and axially or circumferentially when they contact an immovable obstruction in the ground.
U.S. Pat. No. 2,054,129 discloses an agricultural implement having cutting tools mounted on a rotatable hub, the cutting tools being supported in disks of resilient material such as rubber to cushion shock of the cutting implements as they dig into the ground.
U.S. Pat. No. 1,757,511 discloses a cultivator reel having tines which are pivotally mounted for limited pivotal movement on a rotatable hub and biased toward the normal cutting and digging position by coil springs. The tines project through arcuate slots in a drum, the arcuate slots limiting the pivotal movement of the tines as the assembly rotates with the tines digging into the ground.
The rotary hoe tool assembly in accordance with the present invention comprises a plurality of elongated teeth which are pivotally mounted on a rotatable hub for limited arcuate movement both forwardly from as well as rearwardly from a normal unstressed position extending radially from the hub. Wedge shaped compressible spacers are interposed between the teeth to limit such forward and rearward arcuate movement as well as to supply compressive biasing rebound force to the teeth when pressure first applied against such compressible spacers is released. The teeth are free to rebound forwardly of their normal unstressed radial position when the initial rearward pressure is released, so the kicking action of the teeth when they dig into and plow through soil is enhanced. Each tooth as it enters the ground and has rearward pressure applied is able to compress more than the immediately following spacer so there is stored up energy in a plurality of compressible spacers to kick the teeth forward as rearward pressure against them is released. This further enhances the kicking action of the teeth of the rotary hoe tool assembly in accordance with the present invention.